This study will compare the effects of low-dose combination oral contraceptive pills and non-hormonal contraceptive methods on subjective and objective aspects of breastfeeding with the use of questionnaires. In addition a pilot study will be conducted to assess the influence of these contraceptive methods on the hypothalamic-pituitary axis by obtaining serial prolactin levels in response to an acute thyrotropin-releasing hormone (TRH) stimulation test.